The present invention relates to a vehicle air conditioner with a refrigerant circuit.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
The use of refrigerant circuits in vehicle air conditioners is known in the art, with some variants providing a 2-evaporator system, namely a front evaporator and a rear system evaporator. The need for a necessary active refrigerant in the refrigerant circuit varies depending on the interconnection and the active operation of the respective heat transfer.
Electrified vehicles typically require, in addition to the evaporator for the interior or front, a separate cooling circuit for conditioning and temperature control of the energy store typically implemented as a high-voltage battery. Such a coolant circuit is coupled with the refrigerant circuit by way of a heat exchanger, wherein such a heat exchanger is in turn also implemented as an evaporator for cooling an air flow or as a so-called chiller for cooling water.
The use of the refrigerant circuit of the vehicle air conditioner in a heat pump mode for heating the passenger compartment is also known. When operating as a heat pump, the refrigerant circuit is able to heat an air flow or a water flow and discharge this heat to the air of the passenger compartment. The quantity of active refrigerant in the refrigerant circuit required for optimal operation varies in this case also depending on the operation of the vehicle air conditioner, i.e. whether heating or cooling is performed or how many heat exchangers are actively operated.
The different modes of operation of such air conditioners may require different refrigerant charges as an optimum depending on the interconnection of the components.
For example, in a generic vehicle air conditioner, a refrigerant may be suctioned out of the non-active areas and to active areas of the refrigerant circuit by forming a connection between the non-active regions and the active low-pressure side. Alternatively, a connection may be formed between the non-active areas and the high-pressure side for expelling refrigerant from the non-active areas of the refrigerant circuit. In specific operating modes, excess refrigerant may be moved from the active regions of the refrigerant circuit to the non-active areas to regulate the active refrigerant charge by suctioning and removing refrigerant from inactive areas of the refrigerant circuit or components thereof.
It would therefore be desirable and advantageous to obviate prior art shortcomings and to provide an improved solution wherein the required quantity of refrigerant can be provided for each operating mode of the vehicle air conditioner.